1. Field of the Invention
This invention relates to an enclosed structure that can be attached to the exterior wall of an existing or new building, such structure typically being referred to as a patio enclosure, sunroom, or solarium. More particularly, the invention relates to a patio enclosure having a high proportion of windows and a roof and constructed from a framework of composite members and insulating wall panels. Even more particularly, this invention relates to composite plastic members extruded from material having improved thermal characteristics and stability.
2. Description of Prior Art
Patio enclosures and sunrooms are not new to the building industry. When adding onto or remodeling an existing home or other structure, many people turn to the patio enclosure or sunroom. Such rooms are relatively easy for trained technicians to construct and are inexpensive when compared to other improvements that can be made to a home, such as remodeled bathrooms or kitchens. These enclosures have traditionally been constructed of an aluminum frame with windows or glass sections. Aluminum sunrooms are shaped with vertical walls that have a curved transition to the roof, although most may have a marquee roof or gable type roof.
The following United States patents and patent application Publication illustrate various enclosures, non-metallic structural elements used in constructing these enclosures, and the materials used in forming the non-metallic structural elements: U.S. Pat. No. 5,497,594 to Guiseppe et al.; U.S. Pat. No. 5,848,512 to Conn; U.S. Pat. No. 6,003,279 to Schneider; U.S. Pat. No. 6,015,611 to Deaner et al.; U.S. Pat. No. 6,117,924 to Brandt; U.S. Pat. No. 6,248,813 to Zehner; U.S. Pat. No. 6,412,227 to DeZen; U.S. Pat. No. 6,337,138 and U.S. Pat. No. 6,344,504 to Zehner et al.; U.S. Pat. No. 6,460,309 to Schneider; and 2002/0066248 to Buhrts et al.
As discussed in Schneider U.S. Pat. No. 6,003,279 and U.S. Pat. No. 6,460,309, aluminum framed enclosures have several disadvantages. The main problem is poor thermal efficiency. Due to the high rate at which aluminum conducts heat, a room constructed from aluminum cannot stay comfortably cool in the summer, without air conditioning, or warm in the winter, without supplemental heating. This drawback results in dramatically increased cooling and heating costs. Further, a high rate of heat transfer can lead to condensation on the interior surfaces of the aluminum structures. Moreover, many of the windows in aluminum frame type sunrooms are generally installed in such a way that the windows cannot be opened and no screens are present.
Another disadvantage is high maintenance. Aluminum must be painted if chipped and is easily dented. Construction of aluminum rooms is a major disadvantage as well. Because of the nature of the metal, the aluminum pieces must be assembled with external fasteners. External fasteners increase the time of assembly and degrade the overall aesthetics of the room.
In light of these various deficiencies, Schneider U.S. Pat. No. 6,003,279 discloses various structural members, which include reinforced and non-reinforced polyvinyl chloride extrusions, which are joined together at joints using hardware which cannot be seen from inside or outside the enclosure, thereby enhancing the aesthetic appeal of the enclosure. Further, Conn U.S. Pat. No. 5,848,512 and Schneider U.S. Pat. No. 6,460,309 disclose an I-beam that is extruded from plastic and configured such that the vertical spacer wall defines a central passageway that extends between the opposite ends of the beam. Schneider U.S. Pat. No. 6,460,309 is directed to a vinyl roofing system utilizing the channel beam to interconnect roof panels with a roof cap.
In obviating certain problems associated with unwanted condensation and thermal conductivity, many framing enclosure designs have used a “sleeve” approach, wherein the aluminum elements and sections are enclosed within PVC frames. A drawback to this approach is that the aluminum reinforcing still has to be properly insulated from the rest of the vinyl profile. This approach results in massive, bulky sections with high material costs.
A need continues for a low maintenance sunroom/patio enclosure that is economical, has improved thermal efficiency, minimizes thermal condensation arising from thermal transmittance, provides sliding or double hung windows and/or doorway, has an aesthetic appearance, conceals connecting fasteners, and employs fastening components that are easy to use when erecting the enclosure.
Accordingly, a primary object of this invention is the provision of a sunroom/patio enclosure that obtains the benefits of framing elements and sections of polymeric and like material, and achieves the above noted needs.
Another object of this invention is the provision of a sunroom/patio enclosure using frame elements formed of composite PVC to allow parts to have smaller cross-sections without a great degree of internal reinforcing.
As is known, steel has much lower conductivity to thermal loss than aluminum, and has higher strength properties with lower cost. Accordingly, another object of this invention is the elimination of most, if not all, aluminum components from the enclosure product, such as by replacing some frame connecting elements with galvanized steel.
Another object of this invention is the provision of an enclosure structure that shows no screw heads on the inside or the outside of the enclosure room.
A further object of this invention is the provision of an enclosure structure comprised of composite PVC to combine the properties of wood with the maintenance free advantages of vinyl.